Rexel Twinlock Crown 3C F1 Double Ledger Refill Sheets (Pack of 100) 75841. This Rexel Twinlock Crown 3C double ledger refill Pack is designed to provide a totally flexible and configurable accounting system to fit within Twinlock Crown 3C binders. Loose leaf for ease of use, this refill Pack consists of 100 double ledger sheets for complete personalisation. The Crown range of refill Packs includes a wide selection of sheet rulings for all forms of accounting.. . Double ledger100 sheet refill Pack. Loose leaf for individual personalization. Designed for use with Twinlock Crown 3C binders. Dimensions: 229x324mm.