3 days 2 nights Very intense ascent. The first day, a trial under the sun and a short trek for 6 hours, breaks in the shade and for lunch. At the first camp, accommodation in a tent and dinner. Second day. We started for the summit at 2AM (less than 3 hours of sleep), after a very light breakfast. Climbing and descending to the summit took 5.5 hours (be sure to bring poles!!!) After returning, another light breakfast, an hour of rest, and then began the descent into the crater. The hardest part of the trek in our opinion, descending on a quite challenging section, especially after the legs were tired from the first day and the ascent/descent to the summit. About 3 hours descent to the lake, lunch on the shore, unfortunately, the hot springs were cold due to the season. After about an hour of rest, we began the ascent to the Senaru caldera, 3 hours of constant ascents and descents, a challenging route ascending right into the clouds. The legs practically wouldn't move. The second day came out to about 13 hours of constant movement and 15 hours on foot. Then followed 9 hours of poor sleep and the final day. Third day. It should be noted that due to enormous fatigue and movement beyond my ability, I went into a shock state, loss of appetite, toilet issues, shaking, and poor sleep. With great effort, we woke up and began the descent into the jungles of the village of Senaru, lasting about 5 hours, from where we were picked up by car and returned to the hotel. Clearly not enough food and snacks, for the day if there was any appetite at all, we were eating at 2000-2500kcal, and seemed to burn 4000-8000kcal depending on the day. It's worth taking electrolytes and a lot of Snickers, about 10-15 of them. The food on the first day you'll enjoy, the second and third you'll feel nauseous with complete lack of appetite. Toilets are decent only at the first camp, Sembalun, after that only in bushes or in special tents where you'll sleep. As a fisherman, I would advise taking a fishing rod, just for the sake of it, to fish for an hour in the volcano's crater at an altitude of 2000m :) The trek is very tough, especially the 15 hours on foot on the second day, if you're worried, it's worth doing only to the summit for 2 days 1 night or 4 days and 3 nights with a crater visit. The summit ascent is much easier than the descent into the crater, definitely take trekking poles with you. Despite everything, I liked it. I would definitely do it again, but taking my additional food and snacks. As for mybalitrips, poor communication, almost no answers to questions, had to search everything on the supplier's website. They implied transfer a day before the start, but after payment, it turned out they'd only pick us up on the start day.