Excise duty exemption for small scale units clarifies valuation and slab-based duty calculation under the notification. Exemption under Notification No. 175/86-C.E. is based on manufacturer clearances; value means value as determined under Section 4 or tariff values, so eligibility depends on clearance value irrespective of specific or ad valorem duty. Extent of exemption is applied by clearance slabs: the first slab is fully exempt, and for the next slab excise duty is the normal rate reduced by a ten percent advance adjustment of the assessable value, with duty expressed on a per unit basis as illustrated in the cement example.