These refill sets are great additions to Derwent Precision mechanical .5mm and .7mm pencils. The .5mm refill set includes one HB .5mm refill box with 15 HB leads inside, one 2B .5mm refill box with 15 2B leads inside and three replacement erasers. The .7mm refill set includes one HB .7mm refill box with 15 HB leads inside, one 2B .7mm refill box with 15 2B leads inside and three replacement erasers.